Like others here I (at first) misread the title "funnest" for funniest!!!! (& I wondered...which team is the funniest?!!!!!).
Detroit (huge fan of their passing game and the fact that they - most of 'em - win by being gentlemen, not thugs...I have a lot of respect for their players & how they won the CUP in a clean way) Pittsburgh (whether you like Crosby and/or Malkin, you can't deny their entertainment value). Chicago (huge fan of Toews, will watch Chicago just to see more Toews! then again I'll watch New Jersey to see more of Zach Parise!!) Montreal (homer vote but I really do like the players/team...fast, skilled, entertaining, clean/classy, no more arrogant jerks like Mike Ribeiro on the Habs, instead Mtl has good young guys like Kosts bros, Pleks, Gorges, Price...I couldn't be more relieved that the Ribeiro "Ribs"/Theodore/Dagenais/Rejean Houle as GM, Mario Tremblay as coach DAYS ARE OVER!!) Washington (for Ovechkin, Backstrom, Semin, Green, but definitely not for OVERPAID Theo). Edmonton (they are usually fast and entertaining) Buffalo (when they had Drury and McKee) Philly (just 'cause they have lots of depth & it makes it interesting to see all those young, good players they have, but...I don't respect how dirty they can be at times which, imo, they don't need to do...they're good without having to resort to cheap, dirty Bobby Clarke antics...I'm also not a fan of Bobby Clarke )
Calgary caters to a different group. While the other teams are all offensively oriented teams, Calgary is a big-hitting, smash-mouth kind of team. If you'd rather watch fights and brawls, then Calgary would be your choice.
My favorite team is CGY, so I will go with a different one - I'd choose Pittsburgh just because of Crosby.